Nuclear Medicine question and answers graded A+ 2023

Nuclear Medicine question and answers graded A+ 2023What is the radiopharmaceutical used in bone scans? - correct answer Tech-99 diphosphate. The radiolabeled substance must be an analog to Calcium, hydroxyl groups or phosphates. How many phases are there to a typical bone scan? - correct answer Three phases. One phase is immediately after uptake (a blood pool image), then images at 5 minutes, then images at 2-4 hours. Early uptake on the 5 minute images shows acute inflammation. Chronic process would show greatest activity on the delayed images. In regards to the thyroid, what type of radiopharm is most often used treatment of thyroid CA? Why is it useful for this? - correct answer I-131 is used for treatment. It can also be used for imaging in conjunction with Te-99. Although, it also has utility in imaging functional metastatic thyroid tissue because its half life is 8 days and imaging can be performed over several days to allow for adequate concentration in the metastatic tissue and its higher energy allows for imaging of deeper metastatic tissue. Provides high dose of radiation to thyroid but acceptable radiation dose to the rest of the body. Half life of I-131 - correct answer 8.04 days Half life of I-123 - correct answer 13 hours What radioisotope is most often used for thyroid function and imaging? - correct answer I-123. This has a photon energy of 159 keV - This gamma energy allows excellent image capture with limited background activity. In thyroid imaging, what are the guidelines for breastfeeding? - correct answer I-131: Cessation of breast feeding I-123: restart breast feeding after 2-3 days Te-99: Restart after 12-24 hours